Bartonellosis diagnosis requires careful evaluation

LETTER TO EDITOR

Bartonellosis diagnosis requires careful evaluation

Marina Rovani Drummond, PhD Student^I,II; Rovilson Gilioli, PhD^III; Paulo Eduardo Neves Ferreira Velho, MD, PhD^II

^ICenter for Global Health (Johns Hopkins University) Schollarship, Baltimore, Maryland, USA

^IIInternal Medicine Department, Faculdade de Medicina, Universidade Estadual de Campinas, São Paulo, Brazil

^IIIMultidisciplinary Center for Biological Research (CEMIB), Universidade Estadual de Campinas, São Paulo, Brazil

^{Correspondence to}

TO THE EDITOR

Human bartonelloses are emerging infectious diseases. These bacteria clinical spectrum is rapidly increasing as the diagnosis of this infection is considered by doctors and more sensitive laboratory tests are performed. They are potentially fatal, especially in immunocompromised patients.

Although there is a test with optimal sensitivity setting for diagnosis of human¹ or animal² bartonelloses, molecular techniques have been widely used alone or in association with liquid or solid medium isolation.² Nevertheless, false negative results are observed depending on the sensitivity of the technique (single round or nested PCR), serology antigen origin,³ number of copies of Bartonella sp. on the specimen studied,^1,4 and specimen preservation (fresh tissue or paraffin),⁵ among other factors.

Apparently, samples that are products of a pre-enrichment culture have a larger number of copies per nanogram of DNA to be studied. They allow more positive results, as exemplified by the work of Diniz et al. 2009.²

These are fastidious bacteria and their primo-isolation is difficult, even using the necessary conditions, such as media enriched with blood, atmosphere of 5% carbon dioxide, temperature between 35 and 37º C for most human pathogenic species, and environment saturated humidity.¹ The falsenegative serology can, amongst other factors, be associated with differences between strains.³ There are no Brazil-1 strain commercially available antigens. The agents may not always be identified by histology. They may be observed in clumps in angiomatous lesions and are rare in granulomatous reactions.⁴

Thus, the diagnosis of human bartonelloses should be considered for patients with classic manifestations of cat scratch disease, bacillary angiomatosis, or recurrent fever as occur in trench fever.⁷ But it should be also considered for those with severe or recurrent anemia, cholestatic liver, serositis of unknown cause, lymphadenopathy, chronic uveitis, and granulomatous or angioproliferative reactions of undefined etiologies.^1,5

However, negative results of serology, culture, histology, and molecular techniques should be evaluated carefully and, whenever possible, seek the combination of these diagnostic tests. For the authors, the molecular amplification associated with liquid or solid medium isolation should be prioritized.

Submitted on: 10/30/2009

Approved on: 12/01/2009

References

• 1. Velho PE, Pimentel V, Del Negro GM, Okay TS, Diniz PP, Breitschwerdt EB. Severe anemia, panserositis, and cryptogenic hepatitis in an HIV patient infected with Bartonella henselae Ultrastruct Pathol 2007; 31(6):373-7.
• 2. Diniz PP, Billeter SA, Otranto D et al. Molecular documentation of Bartonella infection in dogs in Greece and Italy. J Clin Microbiol 2009; 47(5):1565-7.
• 3. Maurin M, Rolain JM, Raoult D. Comparison of in-house and commercial slides for detection by immunofluorescence of immunoglobulins G and M against Bartonella henselae and Bartonella quintana Clin Diagn Lab Immunol 2002; 9(5):1004-9.
• 4. Velho PE, Souza EM, Cintra ML, de Moraes AM, Uthida-Tanaka AM. Diagnóstico da infecção por Bartonella spp.: a propósito de um caso de angiomatose bacilar. An Bras Dermatol 2006; 81(4):349-53.
• 5. Lamas C, Curi A, Bóia M, Lemos E. Human bartonellosis: seroepidemiological and clinical features with an emphasis on data from Brazil - a review. Mem Inst Oswaldo Cruz 2008; 103(3):221-35.

Publication Dates

• Publication in this collection
  03 Sept 2010
• Date of issue
  June 2010